New hearing aids made for Apple products - that can be personalized and are discreet - could make wearing the devices more appealing.

New on the market this spring are high-tech hearing aids that are compatible with the iPhone, iPad and iPod Touch. They arose from collaborations with Apple, the Cupertino personal computing giant that has shown interest in medical devices.

Audiologists and manufacturers, such as Starkey Hearing Technologies and GN ReSound, hope the devices will appeal to Baby Boomers whose hearing isn't what it used to be. The technology comes at a perfect time, said Thomas Gunderson, a senior health care analyst for Piper Jaffray and Co.

"Everybody's walking around with more computer power than they need in their smartphones," Gunderson said. "We've got a market where 10,000 Baby Boomers are turning 65 every day. We finally have cracked the battery problem. I think it all comes together, and it makes sense that Apple is a leader here."

More than 36 million adults in the United States have some hearing loss, but only 1 out of 5 people who need a hearing aid have one, according to the National Institute on Deafness and Other Communication Disorders.

Industry analysts attribute the gap to hearing aids' decades-old reputation of being large, obvious and bad at filtering out background noise.

That perception has improved in recent years, starting with the first digital hearing aids that became commercially available in the mid-1990s. The devices have increasingly become smaller and more sophisticated.

On Monday, Starkey will release its hearing aid, Halo, which connects to an app available in the App Store. Conversations, music, movies, phone calls and other audio are streamed to the small earpiece, and users can control the volume to precise degrees. In a recent test of the device, conversations unfolding in the next room went from undetectable to slightly audible.

Starkey's app also uses GPS to "remember" the volume settings for up to 20 locations - everything from a crowded cafe to a peaceful library - and automatically adjusts the noise level when the user is in a car.

'Convenience aspect'

The app can also turn an Apple device into a microphone, and includes a feature that helps forgetful users track down misplaced hearing aids.

"We think the convenience aspect of this brings the same hearing function to people with hearing loss as their normal-hearing counterparts," said David Fabry, vice president of audiology and professional relations of Starkey in Minnesota.

Getting your hearing back isn't cheap. The average price of a digital hearing aid is about $1,500, according to the National Institutes of Health. In contrast, a single Halo ranges in price from $1,900 to $2,800, and most people wear two aids at a time.

Meanwhile, a single hearing aid from Denmark competitor GN ReSound, released earlier this year, costs around $3,000. That device, the LiNX, also syncs with an app and has many features similar to the Halo's. Starkey says the Halo has a longer-lasting battery and can remember more geo-tagged locations.

Dr. Kenneth Smith, an audiologist at the Hearing Center of Castro Valley, hasn't tried the Halo but said he believes the LiNX has the most advanced technology in the industry.

"One of our questions was, 'Was the hearing aid a stand-alone without looking at the Apple part of it?' The answer was an unqualified yes," said Smith, who also does consulting for ReSound and tested the company's product on his patients.

Working with Apple

Both ReSound and Starkey developed their hearing aids in partnership with Apple, a move that fits with the company's slow entry into medical devices. Apple is exploring ways to predict heart attacks by studying the sound blood makes as it flows through arteries, as The Chronicle reported last month. Other news outlets have said Apple is working on an app that will allow people to closely track health, fitness and activity information.

It wouldn't be surprising if hearing aids and apps for Android phones came out within a year, Gunderson said. The demand will still be there.

"The Boomers lived through a huge renaissance of rock-and-roll, and it was all part of their young 20 and 30s, but it also might have accelerated their hearing impairment," he said. "At the same time, they still love their music and they want to hear it."